Numerous existing automatic fishing and automatic hook setting devices use combination of a spring device and a triggering device to either lift the fishing rod upward, or to pull the fish line, upon a fish strike. Many of these inventions are fishing rod holder devices. The spring device used in these rod holder type devices is to store energy for lifting the fishing rod, and the trigger device is used to transforming the tug of the line by a fish strike to trigger the release of energy stored in the spring device. U.S. Pat. No. 3,889,413, issued on Jun. 17, 1979 to Robert T. Snider and Jessie G. Zimmerman, U.S. Pat. No. 4,142,315, issued on May 2, 1977 to Gary J. Hoffman, and U.S. Pat. No. 5,542,205, issued on Aug. 6, 1996 to Lester Updike, is among this type of inventions. The combination of a spring device and triggering device in such cases mimics the use of energy stored in the human muscle and reaction of a fisherman to a fish strike.
Combination of a spring device and triggering device for an automatic fishing device usually means that the manufacturing processes of those devices are likely to be complicated, and the cost of such devices can be high. Many fishing rod holder devices are also heavy, not practical to carry around, or easy to setup. Not easy to use or high cost limits the practical application and market acceptance of those devices.
Besides using spring as the store of energy in automatic fishing devices, there are inventors who use a weight instead of spring to store energy. U.S. Pat. No. 4,204,355 issued on May 27, 1980, to William C. Almond, describes a simple automatic fish catcher using a weight for pulling the fish line. This fish catcher uses a horizontal supporting arm to hang a weight, and the fish line is attaches to the weight so that the tightening of the fish line by a fish strike will drag the weight out of the horizontal supporting arm, causing the weight to fall, pulling the fishing with it. Although it is a low cost and easy to use device for automatic fishing, this device has the certain limitations. For example, the arm for supporting the weight has to be set up horizontally. Out of horizontal position will either cause the weight to fall by itself, or make it harder for fish to move the weight outward to fall. The biting fish has to apply considerable force to move such weight outward. This may reduce the effectiveness of the device. Also, the weight of this device needs considerable falling height to lift hooked fish to the water surface; it is not suitable in place of shallow water. This device only works when the direction of the fish bite is away from the fishing device to cause the tightening of the fish line. If fish bites in opposite direction, setting the fish line loose, the weight will stay still, giving opportunity for the fish to escape.
In fact, many automatic fishing devices only work when fish is biting away from the fishing device. They depend on the tightening of fish line to trigger the hook setting devices. They are ineffective when fish is biting toward the fishing device, in such case the fish line is loosening instead of tightening. In general, when movement of the fish cause the fish line to loose, it is much harder for a fisherman to catch the fish with or without an automatic fishing device. Since it is harder to detect the loosening of the line, and it is harder to get the good timing for pulling fishing line.